In a motion capture system having a depth camera, access to an electronic media device such as personal computer or a game console with Internet connectivity is controlled. The age group of a person in a field of view of the camera can be determined based on metrics of a 3-D body model. The metrics can relate to, e.g., a relative size of a head of the body, a ratio of arm length to body height, a ratio of body height to head height, and/or a ratio of head width to shoulder width. The metrics are particularly indicative of age group. Based on the age group, a profile of the user is automatically updated with various parental control settings which control access to the electronic media device. Also, currently output content can be replaced by substitute content when a person in a lower age group enters the field of view.